High data throughput wireless local area network receiver

ABSTRACT

A method for receiving a frame in a high data throughput wireless local area network begins by receiving a preamble of the frame via a channel in accordance with a default receiver filter mask. The processing continues by validating the preamble. The processing continues by, when the preamble is validated, interpreting the preamble to determine a high data throughput channel configuration. The processing continues by reconfiguring the default receiver filter mask in accordance with the high data throughput channel configuration to produce a reconfigured receiver filter mask. The processing continues by receiving a data segment of the frame in accordance with the reconfigured receiver filter mask.

CROSS REFERENCE TO RELATED PATENTS

This patent is claiming priority under 35 USC § 119 (e) to pendingprovisionally filed patent application entitled CONFIGURABLE SPECTRALMASK FOR USE IN A HIGH DATA THROUGHPUT WIRELESS COMMUNICATION, having aprovisional Ser. No. of 60/524,528, and a filing date of Nov. 24, 2003.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

This invention relates generally to wireless communication systems andmore particularly to high data throughput communications in suchsystems.

2. Description of Related Art

Communication systems are known to support wireless and wire linedcommunications between wireless and/or wire lined communication devices.Such communication systems range from national and/or internationalcellular telephone systems to the Internet to point-to-point in-homewireless networks. Each type of communication system is constructed, andhence operates, in accordance with one or more communication standards.For instance, wireless communication systems may operate in accordancewith one or more standards including, but not limited to, IEEE 802.11,Bluetooth, advanced mobile phone services (AMPS), digital AMPS, globalsystem for mobile communications (GSM), code division multiple access(CDMA), local multi-point distribution systems (LMDS),multi-channel-multi-point distribution systems (MMDS), and/or variationsthereof.

Depending on the type of wireless communication system, a wirelesscommunication device, such as a cellular telephone, two-way radio,personal digital assistant (PDA), personal computer (PC), laptopcomputer, home entertainment equipment, et cetera communicates directlyor indirectly with other wireless communication devices. For directcommunications (also known as point-to-point communications), theparticipating wireless communication devices tune their receivers andtransmitters to the same channel or channels (e.g., one of the pluralityof radio frequency (RF) carriers of the wireless communication system)and communicate over that channel(s). For indirect wirelesscommunications, each wireless communication device communicates directlywith an associated base station (e.g., for cellular services) and/or anassociated access point (e.g., for an in-home or in-building wirelessnetwork) via an assigned channel. To complete a communication connectionbetween the wireless communication devices, the associated base stationsand/or associated access points communicate with each other directly,via a system controller, via the public switch telephone network, viathe Internet, and/or via some other wide area network.

For each wireless communication device to participate in wirelesscommunications, it includes a built-in radio transceiver (i.e., receiverand transmitter) or is coupled to an associated radio transceiver (e.g.,a station for in-home and/or in-building wireless communicationnetworks, RF modem, etc.). As is known, the transmitter includes a datamodulation stage, one or more intermediate frequency stages, and a poweramplifier. The data modulation stage converts raw data into basebandsignals in accordance with a particular wireless communication standard.The one or more intermediate frequency stages mix the baseband signalswith one or more local oscillations to produce RF signals. The poweramplifier amplifies the RF signals prior to transmission via an antenna.

As is also known, the receiver is coupled to the antenna and includes alow noise amplifier, one or more intermediate frequency stages, afiltering stage, and a data recovery stage. The low noise amplifierreceives inbound RF signals via the antenna and amplifies them. The oneor more intermediate frequency stages mix the amplified RF signals withone or more local oscillations to convert the amplified RF signal intobaseband signals or intermediate frequency (IF) signals. The filteringstage filters the baseband signals or the IF signals to attenuateunwanted out of band signals to produce filtered signals. The datarecovery stage recovers raw data from the filtered signals in accordancewith the particular wireless communication standard.

The assigned channel, or channels, over which the direct or indirectcommunication occurs is defined by the standard, or standards, supportedby the wireless communication devices. For example, IEEE 802.11 (a) and(g) provide a channel spectral mask for 20 MHz orthogonal frequencydivision multiplexing (OFDM) channels. The standards also define themanner in which devices communicate over the channel. For example, theIEEE 802.11 (a) and (g) standards define a frame structure forcommunicating via a channel in a WLAN. The frame includes a preamble anda variable length data segment. The preamble includes a short trainingsequence, a long training sequence, and a signal field, which providesrate information of the data and length of the data segment.

Each receiving wireless communication device uses the frame preamble forsignal detection, automatic gain control adjustments, diversitydeterminations, frequency adjustments, timing synchronization, andchannel and fine frequency offset estimation. Such a frame format allowsthe wireless communication devices of a WLAN to communicate in a veryspecific manner. This frame format, however, does not accommodate higherdata throughput rates, with backward compatibility to existing WLANequipment, and various wireless channel configurations.

Therefore, a need exists for a method and apparatus of receiving a newframe format that enables wireless communication devices to support avariety of wireless channel configurations and/or high throughput datarates.

BRIEF SUMMARY OF THE INVENTION

The high data throughput wireless local area network receiver of thepresent invention substantially meets these needs and others. In oneembodiment, a method for receiving a frame in a high data throughputwireless local area network begins by, prior to receiving the frame,configuring a receiver filter mask according to a first channel width ofa plurality of channel widths to produce a first configured receiverfilter mask. The processing continues by receiving a first preamblesegment of the frame via a channel, wherein the first preamble segmentincludes a first training sequence, a second training sequence, and ahigh throughput indication, wherein the first training sequence iswithin a first set of subcarriers of the channel and the second trainingsequence is within a second set of subcarriers of the channel, whereinthe first set of subcarriers is a subset of the second set ofsubcarriers in accordance with the first configured receiver filtermask. The processing continues by performing a first validation test onthe first training sequence. The processing continues by, when the firstvalidation test is successful, performing a second validation test ofthe second training sequence. The processing continues by, when thesecond validation test is successful, interpreting the high throughputindication. The processing continues by, when the high throughputindication indicates a high data throughput, receiving a second preamblesegment of the frame via the channel. The processing continues byverifying the second preamble segment to in accordance with areconfigured receiver filter mask. The processing continues by, when thesecond preamble segment is verified, receiving a data segment of theframe in accordance with the reconfigured receiver filter mask.

In another embodiment, a method for receiving a frame in a high datathroughput wireless local area network begins by receiving a preamble ofthe frame via a channel in accordance with a default receiver filtermask. The processing continues by validating the preamble. Theprocessing continues by, when the preamble is validated, interpretingthe preamble to determine a high data throughput channel configuration.The processing continues by reconfiguring the default receiver filtermask in accordance with the high data throughput channel configurationto produce a reconfigured receiver filter mask. The processing continuesby receiving a data segment of the frame in accordance with thereconfigured receiver filter mask.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic block diagram of a wireless communication systemin accordance with the present invention;

FIG. 2 is a schematic block diagram of a wireless communication devicein accordance with the present invention;

FIG. 3 is a diagram depicting frequency bands that may be used inaccordance with the present invention;

FIG. 4 is a diagram depicting channel partitioning of a frequency bandin accordance with the present invention;

FIG. 5 is a diagram of a configurable spectral mask in accordance withan embodiment of the present invention;

FIG. 6 is a table providing parametric examples of the configurablespectral mask of FIG. 5;

FIG. 7 is a diagram of transmitting frames via an RF channel inaccordance with an embodiment of the present invention;

FIG. 8 is a diagram of a frame format in accordance with an embodimentof the present invention;

FIG. 9 is a diagram of channel configurations in accordance with anembodiment of the present invention;

FIG. 10 is a logic diagram of a method for receiving a frame in a highdata throughput wireless local area network in accordance with thepresent invention; and

FIG. 11 is a logic diagram of an alternate method for receiving a framein a high data throughput wireless local area network in accordance withthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram illustrating a communication system10 that includes a plurality of base stations and/or access points12-16, a plurality of wireless communication devices 18-32 and a networkhardware component 34. The wireless communication devices 18-32 may belaptop host computers 18 and 26, personal digital assistant hosts 20 and30, personal computer hosts 24 and 32 and/or cellular telephone hosts 22and 28. The details of the wireless communication devices will bedescribed in greater detail with reference to FIG. 2.

The base stations or access points 12-16 are operably coupled to thenetwork hardware 34 via local area network connections 36, 38 and 40.The network hardware 34, which may be a router, switch, bridge, modem,system controller, et cetera provides a wide area network connection 42for the communication system 10. Each of the base stations or accesspoints 12-16 has an associated antenna or antenna array to communicatewith the wireless communication devices in its area via one or moreconfigurable channels within one or more frequency bands. Typically, thewireless communication devices register with a particular base stationor access point 12-14 to receive services from the communication system10. For direct connections (i.e., point-to-point communications),wireless communication devices communicate directly via an allocatedchannel of the configurable channels.

Typically, base stations are used for cellular telephone systems andlike-type systems, while access points are used for in-home orin-building wireless networks. Regardless of the particular type ofcommunication system, each wireless communication device includes abuilt-in radio and/or is coupled to a radio. The radio includes a highlylinear amplifier and/or programmable multi-stage amplifier as disclosedherein to enhance performance, reduce costs, reduce size, and/or enhancebroadband applications.

FIG. 2 is a schematic block diagram illustrating a wirelesscommunication device that includes the host device 18-32 and anassociated radio 60. For cellular telephone hosts, the radio 60 is abuilt-in component. For personal digital assistants hosts, laptop hosts,and/or personal computer hosts, the radio 60 may be built-in or anexternally coupled component.

As illustrated, the host device 18-32 includes a processing module 50,memory 52, radio interface 54, input interface 58 and output interface56. The processing module 50 and memory 52 execute the correspondinginstructions that are typically done by the host device. For example,for a cellular telephone host device, the processing module 50 performsthe corresponding communication functions in accordance with aparticular cellular telephone standard.

The radio interface 54 allows data to be received from and sent to theradio 60. For data received from the radio 60 (e.g., inbound data), theradio interface 54 provides the data to the processing module 50 forfurther processing and/or routing to the output interface 56. The outputinterface 56 provides connectivity to an output display device such as adisplay, monitor, speakers, et cetera such that the received data may bedisplayed. The radio interface 54 also provides data from the processingmodule 50 to the radio 60. The processing module 50 may receive theoutbound data from an input device such as a keyboard, keypad,microphone, et cetera via the input interface 58 or generate the dataitself. For data received via the input interface 58, the processingmodule 50 may perform a corresponding host function on the data and/orroute it to the radio 60 via the radio interface 54.

Radio 60 includes a host interface 62, digital receiver processingmodule 64, an analog-to-digital converter 66, a filtering/gain module68, an IF mixing down conversion stage 70, a receiver filter 71, a lownoise amplifier 72, a transmitter/receiver switch 73, a localoscillation module 74, memory 75, a digital transmitter processingmodule 76, a digital-to-analog converter 78, a filtering/gain module 80,an IF mixing up conversion stage 82, a power amplifier 84, a transmitterfilter module 85, and an antenna 86. The antenna 86 may be a singleantenna that is shared by the transmit and receive paths as regulated bythe Tx/Rx switch 73, or may include separate antennas for the transmitpath and receive path. The antenna implementation will depend on theparticular standard to which the wireless communication device iscompliant.

The digital receiver processing module 64 and the digital transmitterprocessing module 76, in combination with operational instructionsstored in memory 75, execute digital receiver baseband functions anddigital transmitter baseband functions, respectively. The digitalreceiver functions include, but are not limited to, digital intermediatefrequency to baseband conversion, demodulation, constellation demapping,decoding, and/or descrambling. The digital transmitter functionsinclude, but are not limited to, scrambling, encoding, constellationmapping, modulation, and/or digital baseband to IF conversion. Thedigital receiver and transmitter processing modules 64 and 76 may beimplemented using a shared processing device, individual processingdevices, or a plurality of processing devices. Such a processing devicemay be a microprocessor, micro-controller, digital signal processor,microcomputer, central processing unit, field programmable gate array,programmable logic device, state machine, logic circuitry, analogcircuitry, digital circuitry, and/or any device that manipulates signals(analog and/or digital) based on operational instructions. The memory 75may be a single memory device or a plurality of memory devices. Such amemory device may be a read-only memory, random access memory, volatilememory, non-volatile memory, static memory, dynamic memory, flashmemory, and/or any device that stores digital information. Note thatwhen the processing module 64 and/or 76 implements one or more of itsfunctions via a state machine, analog circuitry, digital circuitry,and/or logic circuitry, the memory storing the corresponding operationalinstructions is embedded with the circuitry comprising the statemachine, analog circuitry, digital circuitry, and/or logic circuitry.

In operation, the radio 60 receives outbound data 94 from the hostdevice via the host interface 62. The host interface 62 routes theoutbound data 94 to the digital transmitter processing module 76, whichprocesses the outbound data 94 in accordance with a particular wirelesscommunication standard (e.g., IEEE 802.11 Bluetooth, et cetera) toproduce digital transmission formatted data 96. The digital transmissionformatted data 96 will be a digital base-band signal or a digital low IFsignal, where the low IF typically will be in the frequency range of onehundred kilohertz to a few megahertz. Further, the digital transmissionformatted data 96 will be based on the channel width of the RF channelon which the data 96 will ultimately be transmitted. For example, thechannel width may be 10 MHz, 20 MHz, or 40 MHz. Continuing with theexample, if the channel is an OFDM (orthogonal frequency divisionmultiplexing) channel, a 10 MHz wide channel may include 32 subcarrierfrequencies, a 20 MHz wide channel may include 64 subcarrierfrequencies, and a 40 MHz wide channel may include 128 subcarrierfrequencies, where the number of subcarriers used per channel is atleast partially based on the spectral masked configured for the channel.Configuring the spectral mask will be described in greater detail withreference to FIGS. 3-6.

The digital-to-analog converter 78 converts the digital transmissionformatted data 96 from the digital domain to the analog domain. Thefiltering/gain module 80 filters and/or adjusts the gain of the analogsignal prior to providing it to the IF mixing stage 82. The IF mixingstage 82 converts the analog baseband or low IF signal into an RF signalbased on a transmitter local oscillation 83 provided by localoscillation module 74. The power amplifier 84 amplifies the RF signal toproduce outbound RF signal 98, which is filtered by the transmitterfilter module 85. The antenna 86 transmits the outbound RF signal 98 toa targeted device such as a base station, an access point and/or anotherwireless communication device. Note that the bandpass regions of thefilters 80 and 85 are dependent upon the configured spectral mask forthe RF transmission, which may be determined by the digital transmitterprocessing module 76.

The radio 60 also receives an inbound RF signal 88 via the antenna 86,which was transmitted by a base station, an access point, or anotherwireless communication device. The antenna 86 provides the inbound RFsignal 88 to the receiver filter module 71 via the Tx/Rx switch 73,where the Rx filter 71 bandpass filters the inbound RF signal 88. The Rxfilter 71 provides the filtered RF signal to low noise amplifier 72,which amplifies the signal 88 to produce an amplified inbound RF signal.The low noise amplifier 72 provides the amplified inbound RF signal tothe IF mixing module 70, which directly converts the amplified inboundRF signal into an inbound low IF signal or baseband signal based on areceiver local oscillation 81 provided by local oscillation module 74.The down conversion module 70 provides the inbound low IF signal orbaseband signal to the filtering/gain module 68. The filtering/gainmodule 68 filters and/or gains the inbound low IF signal or the inboundbaseband signal to produce a filtered inbound signal. Note that thebandpass regions of the filters 71 and 68 are dependent upon theconfigured spectral mask for the RF transmission, which may bedetermined by the receiver processing module 64.

The analog-to-digital converter 66 converts the filtered inbound signalfrom the analog domain to the digital domain to produce digitalreception formatted data 90. The digital receiver processing module 64decodes, descrambles, demaps, and/or demodulates the digital receptionformatted data 90 to recapture inbound data 92 in accordance with theparticular wireless communication standard being implemented by radio 60and the particular channel width of the channel. The host interface 62provides the recaptured inbound data 92 to the host device 18-32 via theradio interface 54.

As one of average skill in the art will appreciate, the wirelesscommunication device of FIG. 2 may be implemented using one or moreintegrated circuits. For example, the host device may be implemented onone integrated circuit, the digital receiver processing module 64, thedigital transmitter processing module 76 and memory 75 may beimplemented on a second integrated circuit, and the remaining componentsof the radio 60, less the antenna 86, may be implemented on a thirdintegrated circuit. As an alternate example, the radio 60 may beimplemented on a single integrated circuit. As yet another example, theprocessing module 50 of the host device and the digital receiver andtransmitter processing modules 64 and 76 may be a common processingdevice implemented on a single integrated circuit. Further, the memory52 and memory 75 may be implemented on a single integrated circuitand/or on the same integrated circuit as the common processing modulesof processing module 50 and the digital receiver and transmitterprocessing module 64 and 76.

FIG. 3 is a diagram depicting a plurality of frequency bands (e.g.,frequency band 1 through frequency band N), which are defined by agovernmental agency for particular wireless applications. For example,the Federal Communications Commission (FCC) defines, for the UnitedStates, frequency bands for specific uses and for which an FCC licenseis required (e.g., radio transmissions, television transmissions, etc.)and also defines frequency bands that are unlicensed and, as such, canbe used for a variety of applications. For instance, the FCC has definedseveral frequency bands in the radio frequency spectrum as beingunlicensed. Such unlicensed frequency bands include 902-928 MHz,2.4-2.483 GHz and 5.75-5.85 GHz, which are collectively referred to asthe ISM (Industrial Scientific Medical) band. Currently, the ISM band isused for in-building and system applications (e.g., bar code readers),industrial microwave ovens, wireless patient monitors, and wirelesslocal area networks (WLAN). In general, the frequency bands of FIG. 3include, but are not limited to, 2.400-2.4835 GHz, 2.471-2.497 GHz,5.15-5.25 GHz, 5.25-5.35 GHz, 5.47-5.725 GHz, 5.725 GHz-5.825 GHz,4.9-5.3 GHz, and 5.85-5.925 GHz.

FIG. 4 is a diagram depicting a particular frequency band that isdivided into a plurality of channels. In accordance with the presentinvention, the channel width of each channel is selectable. As such, fora given frequency band, the number of channels will vary depending onthe selected channel width. For instance, in one embodiment of thepresent invention, the channel width may be selected in accordance withIEEE 802.11 (a) or (g), where IEEE 802.11 (a) provides wireless LANoperation specifications in the 5.15 to 5.35 GHz band. In general, thespecified modulation schemes are based on Orthogonal Frequency DivisionMultiplexing (OFDM) which, for 802.11(a) divides the 5.15 to 5.35 GHzband into eight 20 MHz wide channels centered at 5.18, 5.20, 5.22, 5.24,5.26, 5.28, 5.30, and 5.32 GHz. In another embodiment of the presentinvention, the 5.15 to 5.35 GHz band may be divided into eighteen 10 MHzwide channels, with the first channel centered at 5.165 GHz and theremaining eleven centered at 10 MHz increments therefrom. In yet anotherembodiment of the present invention, the 5.15 to 5.35 GHz band may bedividing into four 40 MHz wide channels, with the channels centered at5.21, 5.25, 5.29, and 5.33 GHz. The same channel width selectivity maybe applied to the 2.4-2.4835 GHz band covered by IEEE 802.11 (g), otherfrequency bands covered by an IEEE 802.11 standard, and/or any otherwireless communication standard. The selectivity of the channel widthprovides for greater data throughput (e.g., at least twice the data rateof IEEE 802.11 (g)), for a diversity of applications, and/or for asingle wireless communication device to support multiple wirelessstandards issued by various standard bodies, including governmentalagencies.

FIG. 5 is a diagram of a configurable spectral mask 100 that includes achannel pass region 102, a transition region 104, and a floor region106. The transition region 104 includes a first attenuation region 108,a second attenuation region 110, and a third attenuation region 112.Such a spectral mask 100 promotes interoperability, coexistence, andsystem capacity by limiting interference to adjacent and other channelsfor a wide variety of applications and/or standards. The out of bandmask (e.g., the transition region 104 and the floor region 106) places alower bound on interference levels that can be expected in receiversregardless of their particular implementation. In an effort to minimizethe interference energy that appears on top of the desired signal, theout of band regions are made as small as possible.

To facilitate the above objective, the channel pass region 102, whichencompasses the desired signal, is of a value as close to the channelbandwidth as feasible. The transition region 104, which bounds theadjacent channel interference and is limited by the bandwidth of thebaseband processing modules 64 and 76 and the intermediate frequencymixing stage of the up-conversion module 82, is selected to minimizesuch interference (i.e., post IF inter-modulation distortion (IMD)). Thefloor region 106, which bounds other channel interference, which isoutside the range of the filters and IMD limits and is generally limitedby the local oscillation 74 phase noise, is selected based on achievablephase noise levels.

For instance, the transition region 104 should have a roll off based onthe shoulder height of IMD, which may be assumed to be produced by a3^(rd) order compressive non-linearity. Based on this assumption, thedistorted transmit signal y(t) as a function of the ideal transmitsignal x(t) can be expressed as: y(t)=x(t)−f(Ax³(t)), where f( ) is abandpass filter that removes any DC or harmonic signals produced by thenon-linearity and A=4/3(1/OIP₃)², where OIP represents “Output 3^(rd)order intercept point”, and in the frequency domainY(f)=X(f)−AX(F)*X(f)*X(f). As such, the distorted signal bandwidth willbe no greater than three times the ideal signal bandwidth.

The floor region 106, which is limited by the local oscillator phasenoise, may be based on L(f) convolved with the power spectral density ofthe ideal transmit signal, where L(f) is defined in IEEE std. 1139-1999as the normalized phase noise spectral density and where y(t)=x(t) l(t)and Y(f)=X(f) * L(f), where x(t) represents the ideal RF signal, l(t) isa model of the phase nose generated in the local oscillator, y(t)represents the resulting signal, and Y(f) is the resulting signal in thefrequency domain. Note that at 10 MHz or more from the carrier, phasenoise spectrum is relatively flat. From this, a −123 dBc/Hz noise floormay be achieved for 20 MHz channels and a −126 dBc/Hz noise floor may beachieved for 40 MHz channels.

FIG. 6 is a table illustrating a few examples of values for aconfigurable spectral mask 100. While the table includes channel widthsof 10, 20, and 40 MHz, one of average skill in the art will appreciateother channel widths may be used. Further, the transition region mayinclude more or less attenuation regions than the three shown in FIG. 5.

FIG. 7 is a diagram illustrating a radio transmitter section 120transmitting frames 126A, 126B via a radio frequency (RF) channel 124 toa radio receiver section 122. The radio transmitter section 120 is inone wireless communication device and corresponds to the digitaltransmitter processing module 76, digital-to-analog converter 78,filter/gain module 80, up-conversion module 82, power amplifier 84 andtransmit filter module 85 of the wireless communication device of FIG.2. The radio receiver section 122, which is in another wirelesscommunication device, corresponds to the digital receiver processingmodule 64, analog-to-digital converter 66, filter/gain module 68,down-conversion module 70, the low noise amplifier 72 and receive filtermodule 71 of the wireless communication device of FIG. 2. The channel124 may be any one of the channels illustrated in FIG. 3 and may haveany spectral mask configuration as described in co-pending patentapplication having a Ser. No. of 60/524,528, entitled CONFIGURABLESPECTRAL MASK FOR USE IN A HIGH DATA THROUGHPUT WIRELESS COMMUNITATION,with a filing date of Nov. 24, 2003.

The format of frames 126A, B includes a 1^(st) preamble section 128, a2^(nd) preamble section 130, and a variable length data segment 132. The1^(st) preamble training segment 128 includes a 1^(st) training sequence134, a 2^(nd) training sequence 136 and a high throughput channelindication 138. The 2^(nd) preamble segment 130 includes a 3^(rd)training sequence 140. In one embodiment, the 1^(st) training sequence134 and 2^(nd) training sequence 136 may correspond to the short andlong training sequences of a preamble in accordance with IEEE802.11a org. The high throughput channel indication 138 is set when thetransmitting radio desires to use a high throughput channelconfiguration. If the high throughput channel indication is not set, the2^(nd) preamble segment 130 would be ignored and the frame would beformatted similarly to legacy wireless local area networks that operatein accordance with IEEE802.11a, b, g, et cetera.

With the high throughput channel indication 138 set, the 3^(rd) trainingsequence 140 of the 2^(nd) preamble segment is implemented to fine-tunethe radio receiver according to the particular channel configuration.The variable length data segment 132 includes a guard interval andassociated data fields. The formatting of frame 126 is described ingreater detail with reference to FIG. 6.

FIG. 8 illustrates the frame 126 in greater detail. As shown, the 1^(st)preamble segment 128 includes the 1^(st) training sequence 134, the2^(nd) training sequence 136 and a signal field. The 1^(st) trainingsequence 134 includes 10 short training sequences that utilize only aportion of the sub-carriers of the particular channel. For instance, thechannel configuration may be a 20 MHz channel bandwidth with 64sub-carriers. The 1^(st) training sequence 134 may only use 12 of the 52data sub-carriers to convey the corresponding short training sequence.The 2^(nd) training sequence 136 includes 2 long training sequences thatmay utilize 52 of the 52 data sub-carriers of a 20 MHz, 64 sub-carrierchannel.

The signal field includes a guard interval (GI) and includes 24 bits ofinformation. The 1^(st) 4 bits correspond to the rate of the datatransmission, the next bit indicates the high through-put channelindication 138, the next 12 bits correspond to the length of thevariable length data segment 132, bit 17 corresponds to the parity ofthe data and the remaining 6 bits correspond to a signal tail.

If the high throughput channel indication 138 is not set, the receivingradio will configure itself based on a default or 1^(st) channelconfiguration which may be the 20 MHz bandwidth channel utilizing 64sub-carriers as currently defined in IEEE802.11a and/or g. If, however,the high throughput channel indication 138 is set, and the receiver iscapable of alternative channel configurations, it will begininterpreting the 2^(nd) preamble.

The 2^(nd) preamble segment 130 includes a channel format identificationfield and a 3^(rd) training sequence 140. The channel identificationfield may include an additional 4-bits for rate information, 5-bits ofchannel configuration information, 12-bits to indicate a trainingmatrix, and the remaining 3-bits may be reserved. As one of averageskill in the art will appreciate, the 24-bits of the channel formatidentification field may be configured in a variety of ways to conveyinformation to the receiving radio as to the bit rate of the highthroughput data, the channel configuration on which the high throughputdata will be conveyed, a diversity antenna arrangement, and a trainingmatrix to produce dual RF transmissions over a single channel.

Once the channel format identification field has been processed, thereceiving radio reconfigures itself based on the channel configurationand the data rate. Having reconfigured itself, the radio receives the3^(rd) training sequence 140 that utilizes a majority of thesub-carriers in accordance with the new channel configuration. Thechannel configurations will be described in greater detail withreference to FIG. 7.

The rate bits in the 1^(st) preamble and 2^(nd) preamble may be used incombination to provide 8-bits of rate information and/or may be usedseparately to provide, in the case of dual communications over a singlepath, to indicate the rates of the separate communications.

The variable length data segment 132 includes a plurality of datasegments and associated guard intervals (GI).

FIG. 9 is a table illustrating the various channel configurations, whichmay be utilized to convey the high data throughput communications. Thechannel configuration table includes a column for the bits to index theparticular channel configuration and configuration information, whichincludes channel bandwidth, number of sub-carriers per channel, rateinterpretation (i.e., are the rate bits in each of the preamble sectionsto be combined or used separately) and space time coding (i.e., thenumber of channel paths that the particular RF channel is supporting).In this example, there are 3 channel bandwidth options, 10 MHz, 20 MHz,and 40 MHz. The default operation of the wireless communication systemin accordance with the present invention would operate as defined inIEEE802.11a or g. As is known, the channel configuration for 802.11Aand/or G includes a 20 MHz channel bandwidth utilizing 64 sub-carrierswhere only 1 path is supported by the RF channel. Hence, the defaultchannel configuration is not in the channel configuration information inthe 2^(nd) preamble section.

If, however, a 20 MHz bandwidth channel is used that has spatial timecoding that supports 2 paths via a single RF channel, then a higher datathroughput is achieved. In one instance, the rate on both channels isthe same corresponding to a rate interpretation of 0, which allows theeight bits (4 from the first preamble segment and 4 from the secondpreamble segment to be combined into one 8 bit code). If the rates forthe 2 paths in space time coding are different, then the rateinterpretation is 1. In this instance, the 4 bits of rate information inthe 1^(st) preamble segment is used to indicate the rate of one of thechannel paths and the 4 bits of rate information in the 2^(nd) preamblesegment are used to indicate the rate of the other channel path.

As is further shown in the table, the 40 MHz channel bandwidth mayinclude 128 sub-carriers and support 1 or 2 paths per channel.Similarly, the 10 MHz channel bandwidth has 64 sub-carriers and maysupport 1 or 2 channel paths.

FIG. 10 is a logic diagram of a method for receiving a frame in a highdata throughput wireless local area network. The processing begins atstep 150, where, prior to receiving the frame, a radio receiverconfigures a receiver filter mask according to a first channel width ofa plurality of channel widths to produce a first configured receiverfilter mask. For example, the first channel width may correspond to a 20MHz channel bandwidth as defined in IEEE 802.11 (a) and/or (g). In otherwords, the receiver will configure its receiver filter mask inaccordance with the spectral mask with which the frame was transmitted.

The process then proceeds to step 152 where the radio receiver receivesa first preamble segment of the frame via a channel. The first preamblesegment includes a first training sequence, a second training sequence,and a high throughput indication. Note that the first training sequenceis within a first set of subcarriers of the channel and the secondtraining sequence is within a second set of subcarriers of the channel,wherein the first set of subcarriers is a subset of the second set ofsubcarriers in accordance with the first configured receiver filtermask. The process then proceeds to step 154 where the radio receiverperforms a first validation test on the first training sequence. Theprocess then proceeds to step 156 where the radio receiver determineswhether the first validation test was successful. If not, the processproceeds to step 158 where the radio receiver deems the frame to beinvalid and it waits for another frame to be received. When a new frameis received, the process continues at step 152.

If, however, the first validation test was successful, the processproceeds to step 160 where the radio receiver performs a secondvalidation test of the second training sequence. The process thenproceeds to step 162 where the radio receiver determines whether thesecond validation test was successful. If not, the process proceeds tostep 158 where the radio receiver deems the frame to be invalid and itwaits for another frame to be received. When a new frame is received,the process continues at step 152.

If, however, the second validation test was successful, the processproceeds to step 164 where the radio receiver interprets the highthroughput indication. In one embodiment, this may be done byinterpreting a channel format field of the second preamble to determinea high data throughput channel configuration. Note that the high datathroughput channel configuration may indicate a second channel width ofthe plurality of channel widths, wherein the second channel width has2^(M) subcarriers received via a single antenna and is greater in widththan the first channel width; a third channel width of the plurality ofchannel widths, wherein the third channel has 2^(K) subcarriers receivedvia the single antenna and is less in width than the first channelwidth; the first channel width having 2^(N) subcarriers received viamultiple antennas; the second channel width having 2^(M) subcarriersreceived via the multiple antennas; and the third channel width having2^(K) subcarriers received via the multiple antennas.

The process then proceeds to step 166 where the radio receiverdetermines whether the high throughput indication indicates a high datathroughput. If not, the process proceeds to step 168 wherein the radioreceiver receives a data segment of the frame via the channel inaccordance with the first configured receiver filter mask. Afterreceiving the remainder of the frame, the process reverts to step 150for a subsequent frame.

If, however, the high throughput indication indicates a high datathroughput, the process proceeds to step 170 wherein the radio receiverreceives a second preamble segment of the frame via the channel. Theprocess then proceeds to step 172 where the radio receiver interprets aconfiguration portion of the second preamble segment to determine a newmask configuration and then reconfigures the receiver filter maskaccordingly.

The process then proceeds to step 174 where the radio receiver verifiesa third training sequence of the second preamble segment to inaccordance with a reconfigured receiver filter mask. This may be done ina variety of ways. In one embodiment, the second preamble segment isverified by: reconfiguring the receiver filter mask according to thesecond channel width to produce the reconfigured receiver filter mask,wherein the channel has a second channel width and includes 2^(M)subcarriers transmitted via the single antenna; and validating a secondchannel width single antenna training sequence of the second preamblesegment in accordance with the reconfigured receiver filter mask.

In another embodiment, the second preamble segment is verified by:reconfiguring the receiver filter mask according to the third channelwidth to produce the reconfigured receiver filter mask, wherein thechannel has a third channel width and includes 2^(K) subcarrierstransmitted via the single antenna; and validating a third channel widthsingle antenna training sequence of the second preamble segment inaccordance with the reconfigured receiver filter mask.

In yet another embodiment, the second preamble segment is verified by:identifying a training matrix from the second preamble segment inaccordance with the first configured receiver filter mask, wherein thechannel has the first channel width and includes 2^(N) subcarrierstransmitted via the multiple antennas; and validating a first channelwidth multiple antenna training sequence of the second preamble segmentin accordance with the first configured receiver filter mask and thetraining matrix, wherein, when the first channel width multiple antennatraining sequence is validated, the receiving the data segment includesreceiving parallel data segments of the frame via the channel inaccordance with the first receiver filter mask and the training matrix.

In further embodiment, the second preamble segment is verified by:reconfiguring the receiver filter mask according to the second channelwidth to produce the reconfigured receiver filter mask, wherein thechannel has second channel width and includes 2^(M) subcarrierstransmitted via the multiple antennas; identifying a training matrixfrom the second preamble segment in accordance with the reconfiguredreceiver filter mask; and validating a second channel width multipleantenna training sequence of the second preamble segment in accordancewith the initial configured receiver filter mask and the trainingmatrix, wherein, when the second channel width multiple antenna trainingsequence is validated, the receiving the data segment includes receivingparallel data segments of the frame in accordance with the reconfiguredreceiver filter mask via the channel in accordance with the reconfiguredreceiver filter mask and the training matrix.

In further embodiment, the second preamble segment is verified by:reconfiguring the receiver filter mask according to the third channelwidth to produce a reconfigured receiver filter mask, wherein thechannel has the third channel width and includes 2^(K) subcarrierstransmitted via the multiple antennas; identifying a training matrixfrom the second preamble segment in accordance with the reconfiguredreceiver filter mask; and validating a third channel width multipleantenna training sequence of the second preamble segment in accordancewith the reconfigured receiver filter mask and the training matrix,wherein, when the third channel width multiple antenna training sequenceis validated, the receiving the data segment includes receiving paralleldata segments of the frame via the channel in accordance with thereconfigured receiver filter mask and the training matrix.

The process then proceeds to step 176 where the radio receiverdetermines whether the second preamble segment has been verified. Ifnot, the process reverts to step 150. If the second preamble wasverified, the process proceeds to step 178 wherein the radio receiverreceives a data segment of the frame in accordance with the reconfiguredreceiver filter mask. Once the frame has been fully received, theprocess repeats at step 150 for a subsequent frame.

FIG. 11 is a logic diagram of a method for receiving a frame in a highdata throughput wireless local area network. The process begins at step180 where a radio receiver receives a preamble of the frame via achannel in accordance with a default receiver filter mask. The processthen proceeds to step 182 where the radio receiver validates thepreamble. The process then proceeds to step 184 where the radio receiverdetermines whether the preamble is validated, which may be done in twoparts: the first part using the default receiver filter mask and thesecond part using a reconfigured receiver filter mask. If it is not, theprocess proceeds to step 186 where the radio receiver determines thatthe current frame is invalid and waits for another frame to be received.

If the preamble is validated, the process proceeds to step 188 where theradio receiver interprets the preamble to determine a high datathroughput channel configuration. The process then proceeds to step 190where the radio receiver reconfigures the default receiver filter maskin accordance with the high data throughput channel configuration toproduce a reconfigured receiver filter mask. The process then proceedsto step 192 where the radio receiver receives a data segment of theframe in accordance with the reconfigured receiver filter mask.

As one of average skill in the art will appreciate, the term“substantially” or “approximately”, as may be used herein, provides anindustry-accepted tolerance to its corresponding term. Such anindustry-accepted tolerance ranges from less than one percent to twentypercent and corresponds to, but is not limited to, component values,integrated circuit process variations, temperature variations, rise andfall times, and/or thermal noise. As one of average skill in the artwill further appreciate, the term “operably coupled”, as may be usedherein, includes direct coupling and indirect coupling via anothercomponent, element, circuit, or module where, for indirect coupling, theintervening component, element, circuit, or module does not modify theinformation of a signal but may adjust its current level, voltage level,and/or power level. As one of average skill in the art will alsoappreciate, inferred coupling (i.e., where one element is coupled toanother element by inference) includes direct and indirect couplingbetween two elements in the same manner as “operably coupled”. As one ofaverage skill in the art will further appreciate, the term “comparesfavorably”, as may be used herein, indicates that a comparison betweentwo or more elements, items, signals, etc., provides a desiredrelationship. For example, when the desired relationship is that signal1 has a greater magnitude than signal 2, a favorable comparison may beachieved when the magnitude of signal 1 is greater than that of signal 2or when the magnitude of signal 2 is less than that of signal 1.

The preceding discussion has presented a radio receiver for processingframes in a high data throughput wireless local area network. As one ofaverage skill in the art will appreciate, other embodiments may bederived from the teachings of the present invention without deviatingfrom the scope of the claims.

1. A method for receiving a frame in a high data throughput wirelesslocal area network, the method comprises: prior to receiving the frame,configuring a receiver filter mask according to a first channel width ofa plurality of channel widths to produce a first configured receiverfilter mask; receiving a first preamble segment of the frame via achannel, wherein the first preamble segment includes a first trainingsequence, a second training sequence, and a high throughput indication,wherein the first training sequence is within a first set of subcarriersof the channel and the second training sequence is within a second setof subcarriers of the channel, wherein the first set of subcarriers is asubset of the second set of subcarriers in accordance with the firstconfigured receiver filter mask; performing a first validation test onthe first training sequence; when the first validation test issuccessful, performing a second validation test of the second trainingsequence; when the second validation test is successful, interpretingthe high throughput indication; when the high throughput indicationindicates a high data throughput, receiving a second preamble segment ofthe frame via the channel; verifying the second preamble segment to inaccordance with a reconfigured receiver filter mask; and when the secondpreamble segment is verified, receiving a data segment of the frame inaccordance with the reconfigured receiver filter mask.
 2. The method ofclaim 1 further comprises: when the high throughput indication does notindicate a high data throughput, receiving a data segment of the framevia the channel in accordance with the first configured receiver filtermask.
 3. The method of claim 1, wherein the interpreting the secondpreamble segment comprises: interpreting a channel format field of thesecond preamble to determine a high data throughput channelconfiguration.
 4. The method of claim 3, wherein the high datathroughput channel configuration comprises at least one of: a secondchannel width of the plurality of channel widths, wherein the secondchannel width has 2^(M) subcarriers received via a single antenna and isgreater in width than the first channel width; a third channel width ofthe plurality of channel widths, wherein the third channel has 2^(K)subcarriers received via the single antenna and is less in width thanthe first channel width; the first channel width having 2^(N)subcarriers received via multiple antennas; the second channel widthhaving 2^(M) subcarriers received via the multiple antennas; and thethird channel width having 2^(K) subcarriers received via the multipleantennas.
 5. The method of claim 4 further comprises: when the high datathroughput channel configuration is the second channel width having2^(M) subcarriers transmitted via the single antenna, validating thesecond preamble segment includes: reconfiguring the receiver filter maskaccording to the second channel width to produce the reconfiguredreceiver filter mask; and validating a second channel width singleantenna training sequence of the second preamble segment in accordancewith the reconfigured receiver filter mask.
 6. The method of claim 4further comprises: when the high data throughput channel configurationis the third channel width having 2^(K) subcarriers transmitted via thesingle antenna, validating the second preamble segment includes:reconfiguring the receiver filter mask according to the third channelwidth to produce the reconfigured receiver filter mask; and validating athird channel width single antenna training sequence of the secondpreamble segment in accordance with the reconfigured receiver filtermask.
 7. The method of claim 4 further comprises: when the high datathroughput channel configuration is the first channel width having 2^(N)subcarriers transmitted via the multiple antennas, validating the secondpreamble segment includes: identifying a training matrix from the secondpreamble segment in accordance with the first configured receiver filtermask; and validating a first channel width multiple antenna trainingsequence of the second preamble segment in accordance with the firstconfigured receiver filter mask and the training matrix, wherein, whenthe first channel width multiple antenna training sequence is validated,the receiving the data segment includes receiving parallel data segmentsof the frame via the channel in accordance with the first receiverfilter mask and the training matrix.
 8. The method of claim 4 furthercomprises: when the high data throughput channel configuration is thesecond channel width having 2^(M) subcarriers transmitted via themultiple antennas, validating the second preamble segment includes:reconfiguring the receiver filter mask according to the second channelwidth to produce the reconfigured receiver filter mask; identifying atraining matrix from the second preamble segment in accordance with thereconfigured receiver filter mask; and validating a second channel widthmultiple antenna training sequence of the second preamble segment inaccordance with the initial configured receiver filter mask and thetraining matrix, wherein, when the second channel width multiple antennatraining sequence is validated, the receiving the data segment includesreceiving parallel data segments of the frame in accordance with thereconfigured receiver filter mask via the channel in accordance with thereconfigured receiver filter mask and the training matrix.
 9. The methodof claim 4 further comprises: when the high data throughput channelconfiguration is the third channel width having 2^(K) subcarrierstransmitted via the multiple antennas, validating the second preamblesegment includes: reconfiguring the receiver filter mask according tothe third channel width to produce a reconfigured receiver filter mask;identifying a training matrix from the second preamble segment inaccordance with the reconfigured receiver filter mask; and validating athird channel width multiple antenna training sequence of the secondpreamble segment in accordance with the reconfigured receiver filtermask and the training matrix, wherein, when the third channel widthmultiple antenna training sequence is validated, the receiving the datasegment includes receiving parallel data segments of the frame via thechannel in accordance with the reconfigured receiver filter mask and thetraining matrix.
 10. A method for receiving a frame in a high datathroughput wireless local area network, the method comprises: receivinga preamble of the frame via a channel in accordance with a defaultreceiver filter mask; validating the preamble; when the preamble isvalidated, interpreting the preamble to determine a high data throughputchannel configuration; reconfiguring the default receiver filter mask inaccordance with the high data throughput channel configuration toproduce a reconfigured receiver filter mask; and receiving a datasegment of the frame in accordance with the reconfigured receiver filtermask.
 11. The method of claim 10, wherein the high data throughputchannel configuration comprises at least one of: a first channel widthof a plurality of channel widths, wherein the first channel width has2^(N) subcarriers received via a single antenna; a second channel widthof the plurality of channel widths, wherein the second channel width has2^(M) subcarriers received via the single antenna and is greater inwidth than the first channel width; a third channel width of theplurality of channel widths, wherein the third channel has 2^(K)subcarriers received via the single antenna and is less in width thanthe first channel width; the first channel width having 2^(N)subcarriers received via multiple antennas; the second channel widthhaving 2^(M) subcarriers received via the multiple antennas; and thethird channel width having 2^(K) subcarriers received via the multipleantennas.
 12. The method of claim 11 further comprises: when the highdata throughput channel configuration is the second channel width having2^(M) subcarriers transmitted via the single antenna, interpreting thepreamble includes: reconfiguring the receiver filter mask according tothe second channel width to produce the reconfigured receiver filtermask; and validating a second channel width single antenna trainingsequence of the second preamble segment in accordance with thereconfigured receiver filter mask.
 13. The method of claim 11 furthercomprises: when the high data throughput channel configuration is thethird channel width having 2^(K) subcarriers transmitted via the singleantenna, interpreting the preamble includes: reconfiguring the receiverfilter mask according to the third channel width to produce thereconfigured receiver filter mask; and validating a third channel widthsingle antenna training sequence of the second preamble segment inaccordance with the reconfigured receiver filter mask.
 14. The method ofclaim 11 further comprises: when the high data throughput channelconfiguration is the first channel width having 2^(N) subcarrierstransmitted via the multiple antennas, interpreting the preambleincludes: reconfiguring the receiver filter mask according to the firstchannel width to produce the reconfigured receiver filter mask;identifying a training matrix from the preamble in accordance with thefirst configured receiver filter mask; and validating a first channelwidth multiple antenna training sequence of the second preamble segmentin accordance with the first configured receiver filter mask and thetraining matrix, wherein, when the first channel width multiple antennatraining sequence is validated, the receiving the data segment includesreceiving parallel data segments of the frame via the channel inaccordance with the first receiver filter mask and the training matrix.15. The method of claim 11 further comprises: when the high datathroughput channel configuration is the second channel width having2^(M) subcarriers transmitted via the multiple antennas, interpretingthe second preamble segment includes: reconfiguring the receiver filtermask according to the second channel width to produce the reconfiguredreceiver filter mask; identifying a training matrix from the secondpreamble segment in accordance with the reconfigured receiver filtermask; and validating a second channel width multiple antenna trainingsequence of the second preamble segment in accordance with the initialconfigured receiver filter mask and the training matrix, wherein, whenthe second channel width multiple antenna training sequence isvalidated, the receiving the data segment includes receiving paralleldata segments of the frame in accordance with the reconfigured receiverfilter mask via the channel in accordance with the reconfigured receiverfilter mask and the training matrix.
 16. The method of claim 11 furthercomprises: when the high data throughput channel configuration is thethird channel width having 2^(K) subcarriers transmitted via themultiple antennas, interpreting the second preamble segment includes:reconfiguring the receiver filter mask according to the third channelwidth to produce a reconfigured receiver filter mask; identifying atraining matrix from the second preamble segment in accordance with thereconfigured receiver filter mask; and validating a third channel widthmultiple antenna training sequence of the second preamble segment inaccordance with the reconfigured receiver filter mask and the trainingmatrix, wherein, when the third channel width multiple antenna trainingsequence is validated, the receiving the data segment includes receivingparallel data segments of the frame via the channel in accordance withthe reconfigured receiver filter mask and the training matrix.
 17. Themethod of claim 10, wherein the validating the preamble comprises:verifying a training sequence in accordance with the default receiverfilter mask.
 18. The method of claim 17 further comprises: verifying asecond training sequence in accordance with the reconfigured receiverfilter mask prior to receiving the data segment.
 19. A radio receivercomprises: a radio frequency (RF) front end operably coupled to convertinbound RF signals into inbound baseband signals; processing module; andmemory operably coupled to the processing module, wherein the memorystores operational instructions that cause the processing module to:prior to receiving a frame of the inbound baseband signals, configure areceiver filter mask according to a first channel width of a pluralityof channel widths to produce a first configured receiver filter mask;interpret a first preamble segment of the frame to identify a firsttraining sequence, a second training sequence, and a high throughputindication, wherein the first training sequence is within a first set ofsubcarriers of the channel and the second training sequence is within asecond set of subcarriers of the channel, wherein the first set ofsubcarriers is a subset of the second set of subcarriers in accordancewith the first configured receiver filter mask; perform a firstvalidation test on the first training sequence; when the firstvalidation test is successful, perform a second validation test of thesecond training sequence; when the second validation test is successful,interpret the high throughput indication; when the high throughputindication indicates a high data throughput, validate the secondpreamble segment to in accordance with a reconfigured receiver filtermask; and when the second preamble segment is validated, receive a datasegment of the frame in accordance with the reconfigured receiver filtermask.
 20. The radio receiver of claim 19, wherein the memory furtherstores operational instructions that cause the processing module to:when the high throughput indication does not indicate a high datathroughput, process a data segment of the frame via the channel inaccordance with the first configured receiver filter mask.
 21. The radioreceiver of claim 19, wherein the memory further stores operationalinstructions that cause the processing module to interpret the secondpreamble segment by: interpreting a channel format field of the secondpreamble to determine a high data throughput channel configuration. 22.The radio receiver of claim 21, wherein the high data throughput channelconfiguration comprises at least one of: a second channel width of theplurality of channel widths, wherein the second channel width has 2^(M)subcarriers received via a single antenna and is greater in width thanthe first channel width; a third channel width of the plurality ofchannel widths, wherein the third channel has 2^(K) subcarriers receivedvia the single antenna and is less in width than the first channelwidth; the first channel width having 2^(N) subcarriers received viamultiple antennas; the second channel width having 2^(M) subcarriersreceived via the multiple antennas; and the third channel width having2^(K) subcarriers received via the multiple antennas.
 23. The radioreceiver of claim 22, wherein the memory further stores operationalinstructions that cause the processing module to: when the high datathroughput channel configuration is the second channel width having2^(M) subcarriers transmitted via the single antenna, validate thesecond preamble segment by: reconfiguring the receiver filter maskaccording to the second channel width to produce the reconfiguredreceiver filter mask; and validating a second channel width singleantenna training sequence of the second preamble segment in accordancewith the reconfigured receiver filter mask.
 24. The radio receiver ofclaim 22, wherein the memory further stores operational instructionsthat cause the processing module to: when the high data throughputchannel configuration is the third channel width having 2^(K)subcarriers transmitted via the single antenna, validate the secondpreamble segment by: reconfiguring the receiver filter mask according tothe third channel width to produce the reconfigured receiver filtermask; and validating a third channel width single antenna trainingsequence of the second preamble segment in accordance with thereconfigured receiver filter mask.
 25. The radio receiver of claim 22,wherein the memory further stores operational instructions that causethe processing module to: when the high data throughput channelconfiguration is the first channel width having 2^(N) subcarrierstransmitted via the multiple antennas, validate the second preamblesegment by: identifying a training matrix from the second preamblesegment in accordance with the first configured receiver filter mask;and validating a first channel width multiple antenna training sequenceof the second preamble segment in accordance with the first configuredreceiver filter mask and the training matrix, wherein, when the firstchannel width multiple antenna training sequence is validated, thereceiving the data segment includes receiving parallel data segments ofthe frame via the channel in accordance with the first receiver filtermask and the training matrix.
 26. The radio receiver of claim 22,wherein the memory further stores operational instructions that causethe processing module to: when the high data throughput channelconfiguration is the second channel width having 2^(M) subcarrierstransmitted via the multiple antennas, validate the second preamblesegment by: reconfigure the receiver filter mask according to the secondchannel width to produce the reconfigured receiver filter mask; identifya training matrix from the second preamble segment in accordance withthe reconfigured receiver filter mask; and validate a second channelwidth multiple antenna training sequence of the second preamble segmentin accordance with the initial configured receiver filter mask and thetraining matrix, wherein, when the second channel width multiple antennatraining sequence is validated, the receiving the data segment includesreceiving parallel data segments of the frame in accordance with thereconfigured receiver filter mask via the channel in accordance with thereconfigured receiver filter mask and the training matrix.
 27. The radioreceiver of claim 22, wherein the memory further stores operationalinstructions that cause the processing module to: when the high datathroughput channel configuration is the third channel width having 2^(K)subcarriers transmitted via the multiple antennas, validate the secondpreamble segment by: reconfiguring the receiver filter mask according tothe third channel width to produce a reconfigured receiver filter mask;identifying a training matrix from the second preamble segment inaccordance with the reconfigured receiver filter mask; and validating athird channel width multiple antenna training sequence of the secondpreamble segment in accordance with the reconfigured receiver filtermask and the training matrix, wherein, when the third channel widthmultiple antenna training sequence is validated, the receiving the datasegment includes receiving parallel data segments of the frame via thechannel in accordance with the reconfigured receiver filter mask and thetraining matrix.
 28. A radio receiver comprises: a radio frequency (RF)front end operably coupled to convert inbound RF signals into inboundbaseband signals; processing module; and memory operably coupled to theprocessing module, wherein the memory stores operational instructionsthat cause the processing module to: identify a preamble of the framevia a channel in accordance with a default receiver filter mask;validate the preamble; when the preamble is validated, interpret thepreamble to determine a high data throughput channel configuration;reconfigure the default receiver filter mask in accordance with the highdata throughput channel configuration to produce a reconfigured receiverfilter mask; and process a data segment of the frame in accordance withthe reconfigured receiver filter mask.
 29. The radio receiver of claim28, wherein the high data throughput channel configuration comprises atleast one of: a first channel width of a plurality of channel widths,wherein the first channel width has 2^(N) subcarriers received via asingle antenna; a second channel width of the plurality of channelwidths, wherein the second channel width has 2^(M) subcarriers receivedvia the single antenna and is greater in width than the first channelwidth; a third channel width of the plurality of channel widths, whereinthe third channel has 2^(K) subcarriers received via the single antennaand is less in width than the first channel width; the first channelwidth having 2^(N) subcarriers received via multiple antennas; thesecond channel width having 2^(M) subcarriers received via the multipleantennas; and the third channel width having 2^(K) subcarriers receivedvia the multiple antennas.
 30. The radio receiver of claim 29, whereinthe memory further stores operational instructions that cause theprocessing module to: when the high data throughput channelconfiguration is the second channel width having 2^(M) subcarrierstransmitted via the single antenna, interpret the preamble by:reconfiguring the receiver filter mask according to the second channelwidth to produce the reconfigured receiver filter mask; and validating asecond channel width single antenna training sequence of the secondpreamble segment in accordance with the reconfigured receiver filtermask.
 31. The radio receiver of claim 29, wherein the memory furtherstores operational instructions that cause the processing module to:when the high data throughput channel configuration is the third channelwidth having 2^(K) subcarriers transmitted via the single antenna,interpret the preamble by: reconfiguring the receiver filter maskaccording to the third channel width to produce the reconfiguredreceiver filter mask; and validating a third channel width singleantenna training sequence of the second preamble segment in accordancewith the reconfigured receiver filter mask.
 32. The radio receiver ofclaim 29, wherein the memory further stores operational instructionsthat cause the processing module to: when the high data throughputchannel configuration is the first channel width having 2^(N)subcarriers transmitted via the multiple antennas, interpret thepreamble by: reconfiguring the receiver filter mask according to thefirst channel width to produce the reconfigured receiver filter mask;identifying a training matrix from the preamble in accordance with thefirst configured receiver filter mask; and validating a first channelwidth multiple antenna training sequence of the second preamble segmentin accordance with the first configured receiver filter mask and thetraining matrix, wherein, when the first channel width multiple antennatraining sequence is validated, the receiving the data segment includesreceiving parallel data segments of the frame via the channel inaccordance with the first receiver filter mask and the training matrix.33. The radio receiver of claim 29, wherein the memory further storesoperational instructions that cause the processing module to: when thehigh data throughput channel configuration is the second channel widthhaving 2^(M) subcarriers transmitted via the multiple antennas,interpret the second preamble segment by: reconfiguring the receiverfilter mask according to the second channel width to produce thereconfigured receiver filter mask; identifying a training matrix fromthe second preamble segment in accordance with the reconfigured receiverfilter mask; and validating a second channel width multiple antennatraining sequence of the second preamble segment in accordance with theinitial configured receiver filter mask and the training matrix,wherein, when the second channel width multiple antenna trainingsequence is validated, the receiving the data segment includes receivingparallel data segments of the frame in accordance with the reconfiguredreceiver filter mask via the channel in accordance with the reconfiguredreceiver filter mask and the training matrix.
 34. The radio receiver ofclaim 29, wherein the memory further stores operational instructionsthat cause the processing module to: when the high data throughputchannel configuration is the third channel width having 2^(K)subcarriers transmitted via the multiple antennas, interpret the secondpreamble segment by: reconfiguring the receiver filter mask according tothe third channel width to produce a reconfigured receiver filter mask;identifying a training matrix from the second preamble segment inaccordance with the reconfigured receiver filter mask; and validating athird channel width multiple antenna training sequence of the secondpreamble segment in accordance with the reconfigured receiver filtermask and the training matrix, wherein, when the third channel widthmultiple antenna training sequence is validated, the receiving the datasegment includes receiving parallel data segments of the frame via thechannel in accordance with the reconfigured receiver filter mask and thetraining matrix.
 35. The radio receiver of claim 29, wherein the memoryfurther stores operational instructions that cause the processing moduleto validate the preamble by: verifying a training sequence in accordancewith the default receiver filter mask.
 36. The radio receiver of claim35, wherein the memory further stores operational instructions thatcause the processing module to: verify a second training sequence inaccordance with the reconfigured receiver filter mask prior to receivingthe data segment.